Abstract: Herein disclosed is a measuring device such as a micrometer, slide calipers, a depth gauge or a height gauge, in which a slider is so provided that it can move back and forth in the same direction of such a relatively movable portion as can move relative to a frame and that it can be fixed on said frame at any position in the forward and backward moving directions thereof, and in which there is interposed between said slider and said relatively movable portion such spring bias means as can apply its spring force to said relatively movable portion in the forward and backward moving directions of the same, whereby the measuring pressure to be applied to a test piece by said relatively movable portion can be automatically predetermined at a substantially constant level independently of the position of said relatively movable portion relative to said frame.