Optical system for shape measuring device

This optical system for a shape measuring device comprises a parallel light irradiation system and an imaging optical system. The parallel light irradiation system includes: a point light source; a collimator lens; and a telecentric lens having a telecentric structure on both sides or the object side, the telecentric lens being irradiated with light from the collimator lens across an object to be measured. The imaging optical system includes an image sensor onto which an image of a portion of the object to be measured by light that has passed through the telecentric lens is projected. The point light source includes: an LED; a diffusion member that diffuses and emits light from the LED; and a pinhole member in which is formed a pinhole on which light from the diffusion member is incident.