From the history of the breed: 
Württemberg and Bavaria in Germany are considered to be a homeland of Giant Schnauzers. According to the Germans' opinion their ancestors were shepherd dogs. But it is commonly supposed that the majority of wirehaired dogs are descendants of hunting dogs, who have been spread long ago throughout Europe. There is another version that Giant Schnauzer originates from big wirehaired pinschers, who were widespread in Bavaria, near Munich. Less often, this dog was called "Russian Schnauzer" or "Bear Schnauzer." But the roots of Russian origin have not been confirmed. 
Country of origin: 
Germany. 
General appearance:
Strong, brave, hardy, assertive dog, with sound and reliable temperament, distrustful for strangers; excellent movements make him one of the most powerful and enduring working dogs; great to be kept in kennels and apartments. 
Height:
Males - 25 1/2 - 27 1/2 inches (65-70 cm), females - 23 1/2 – 25 1/2 inches (60-65 cm). 
Weight: 
55–80 pounds (25–36 kg).

Format: 
Square. 
Coat:
Hard, wiry, thick and slightly-standing of the body. The undercoat is soft. Coarse hair is on the head, beard and eyebrows (the hallmark of Schnauzers). 
Color:
Pure black with black undercoat. A small white patch on the chest is allowed. Pepper-and-salt is also possible. In ideal: rich grey color with "pepper" distributed all over the body with gray undercoat. 
Also all shades of "pepper-and-salt" are allowed, from dark steel-gray to silver-gray. There must be dark facial mask to emphasize the expression. Eyebrows, inside ears, whiskers, cheeks, throat, chest, legs, and under tail are lighter in color but include peppering. 
Head: 
Strong, elongated, gradually narrowing from the ears to the tip of the powerful, ferreting snout, rectangular in appearance and in proportion to the sex and substance of the dog. The length of the head is one-half the length of the back from withers to the base of the tail. The lines of skull and muzzle are parallel; stop is well-defined with the eyebrows. Skull is moderately broad between the ears, occiput is not prominent. 
Ears:
Ears are cropped, set high, V-shaped with inner edges lying close to the cheeks, evenly carried, turned forward towards temples. Folds parallel, should not be above the top of the skull. 
Eyes: 
Of medium size, dark brown, deep set. Oval with tight-fitting lids, keen expression. Vision should be excellent, eyes should not be covered with too long eyebrows. 
Neck: 
Strong, arched, of medium length, blending smoothly into the withers, in harmony with the dog; dry skin, without wrinkles and folds on the throat. 
Teeth: 
White teeth with scissors bite. The upper and lower jaws are strong, well-formed.

Body: 
Compact, substantial, short-coupled and strong, with great power and agility. Height at the withers equals the length of the body. Loin is strong, well-muscled, short. The length of the dog from sternum to point of rump is equal to the height at the withers. 
Chest: 
Moderately broad and deep, ribs are prominent enough, but not barrel-shaped. Strong sternum (breastbone), reaching at least down to the elbow, and slowly tapering up and back to croup. Shoulders are oblique, flat, covered with strong muscles. 
Belly: 
Moderately tucked up, forming a well curved line with the underside of the ribcage. 
Tail: 
Set moderately high, carried high in excitement, from 2-4 inches long (5-10 cm), docked to the second or third joint. 
Limbs: 
Forequarters: when seen from the front, the front legs are strong, straight and set not close to each other. Forefeet are short and round, toes well-knit and arched (cat foot) with short dark nails and resistant pads. 
Hindquarters: standing obliquely when seen from the side, standing parallel but not close together when seen from the rear. Thighs are muscular and strong, broad and long. Hocks are strong and firm. Hind feet are short and well-knit, with dark short nails. 
Attractive features: 
Giant Schnauzer is a well-balanced dog, lively, courageous, incorruptible and devoted to his owner. He is hardy, unpretentious, flexible, easily trained. Many experienced breeders say that the skills and the abilities of Giant Schnauzer do not come short of German Shepherd ones. And indeed, one has to agree with this fact. Ideal muscular build, intelligence, excellent working abilities are the key features of working dogs.