A small-sized measuring device includes a position detector that is provided on a main body and detects the position of an object to be measured, a photosensor, and a central control unit that controls overall operation. The photosensor is configured to function at least as an input device configured to accept a base-point setting instruction from the user. The central control unit, when accepting the base-point setting instruction from the user through the non-contact input sensor, performs a base-point setting step of setting the position of the object to be measured detected by the position detector as a base point, and performs a measurement step of measuring the position of the object to be measured as a relative position from the base point.