A semiconductor device (100) includes: a first thin film transistor (105) of a first conductivity type formed on a substrate for each pixel; and a plurality of photosensor sections (200). Each photosensor section (200) includes a photodetecting portion including a thin film diode (202), a capacitor (206) for storing a photocurrent occurring in the thin film diode (202), and a second thin film transistor (204) of the first conductivity type, the photodetecting portion being connected to the capacitor (206) via the second thin film transistor (204); the first and second thin film transistors (105, 204) and the thin film diode (202) have semiconductor layers made of the same semiconductor film; and a characteristic of the first thin film transistor (105) and a characteristic of the second thin film transistor (204) are different. As a result, the characteristics of the thin film transistors for use in the pixels and the thin film transistors for use in the photosensor sections can be controlled in accordance with the characteristics required of the respective thin film transistors.