A lancet device with an adjustable hypodermic penetration depth, comprising: a lancet holder having a lancet seat to mount a lancet at one end; an operating mechanism disposed at the other end of the lancet holder and loading and releasing the lancet holder along a predetermined path; a depth adjusting member receiving the lancet holder and having at least two grooves formed at a predetermined angle on the circumferential surface of one end to form inclined passages (141, 141'. 141") clockwise or counterclockwise; and a housing receiving the lancet holder and the operating mechanism, characterized in that said housing has a protrusion that is formed on the inner side of an end and is fitted step by step in the grooves when the depth adjusting member turns at a predetermined angle, the housing further including: a first housing part receiving the operating mechanism; and a second housing part rotating about the axis of the first housing part, combined with the depth adjusting member therein, and having the protrusion, the inclined passages and the grooves are formed symmetrically with a gap of 180 degrees, two pieces of the protrusion are formed symmetrically with a gap of 180 degrees and the hypodermic penetration depth of lancet needle of the lancet is adjusted from 1.7 to 2.0mm in ten steps, and a hollow space is defined above the protrusion. a lancet holder having a lancet seat to mount a lancet at one end; an operating mechanism disposed at the other end of the lancet holder and loading and releasing the lancet holder along a predetermined path; a depth adjusting member receiving the lancet holder and having at least two grooves formed at a predetermined angle on the circumferential surface of one end to form inclined passages (141, 141'. 141") clockwise or counterclockwise; and a housing receiving the lancet holder and the operating mechanism, characterized in that said housing has a protrusion that is formed on the inner side of an end and is fitted step by step in the grooves when the depth adjusting member turns at a predetermined angle, the housing further including: a first housing part receiving the operating mechanism; and a second housing part rotating about the axis of the first housing part, combined with the depth adjusting member therein, and having the protrusion, the inclined passages and the grooves are formed symmetrically with a gap of 180 degrees, two pieces of the protrusion are formed symmetrically with a gap of 180 degrees and the hypodermic penetration depth of lancet needle of the lancet is adjusted from 1.7 to 2.0mm in ten steps, and a hollow space is defined above the protrusion. a first housing part receiving the operating mechanism; and a second housing part rotating about the axis of the first housing part, combined with the depth adjusting member therein, and having the protrusion, the inclined passages and the grooves are formed symmetrically with a gap of 180 degrees, two pieces of the protrusion are formed symmetrically with a gap of 180 degrees and the hypodermic penetration depth of lancet needle of the lancet is adjusted from 1.7 to 2.0mm in ten steps, and a hollow space is defined above the protrusion.