A method for producing a half mirror includes forming a reflection region by which light is reflected and a transmission region through which the light is transmitted on a surface of a transparent plate Only the reflection region is coated with a plating. The coating includes a masking step of coating a position of the transparent plate corresponding to the transmission region with a masking material, a plating step of coating the entire surface which includes the transmission region which has been coated with the masking material and the reflection region with the plating, a plating removing step of removing the plating to a depth in which the masking material is exposed after the plating step, and a masking material removing step of removing the masking material after the plating removing step.