An intraoral scanner includes a casing, a light source disposed in the casing, a reflection plate obliquely disposed in the casing for reflecting light of the light source to an object to be scanned through an opening of the casing, a transparent plate, and a receiver adjacent to the light source. A projection optical axis of the light source forms a first oblique angle with a receiving optical axis of the receiver. The receiver receives light after being incident to the object to be scanned and then reflected to the receiver by the reflection plate. The transparent plate is disposed between the light source and the reflection plate or covers the opening. The projection optical axis forms a second oblique angle with a norm of the transparent plate to make a reflection angle range of light reflected by the transparent plate fall outside a receiving angel range of the receiver.