Patent attributes
A shape measuring instrument is provided as being capable of measuring a surface shape of a target with a small contact force while changing the contact force. A measuring probe 32 is supported while a tilt θ is provided. A retracting force of the measuring force 32 is produced by the tilt θ, and thus, is obtained as mgsig θ which is much small as compared with a self weight “m”. On the other hand, biasing is provided with an extruding force Fc by means of an air cylinder 40. Thus, a contact force of the measuring probe 32 relevant to a work piece W is obtained as a difference between a measuring probe self weight tilt component mgsigθ and the extruding force Fc of the air cylinder 40 (F=Fc−mgsigθ), thus making it possible to reduce a contact force to be very small.