A surface texture measuring machine includes: a stage, a contact-type detector having a stylus, an image probe, a relative movement mechanism and a controller. The controller includes: a center position calculating unit that, when the image probe enters position data of at least three points on a circular contour of a circular concave portion or a circular convex portion of an object, approximates the entered position data to a circle to obtain a center position of the circle; and a stylus setting unit that, after calculating the center position, operates the relative movement mechanism to position the stylus of the contact-type detector at the center position.