Provided is a semiconductor device in which change in characteristics of a transistor is suppressed and an output signal is changed sharply without increasing W/L of the transistor can be provided. Two transistors are connected in parallel between a wiring to which a low potential is supplied and an output terminal. When the low potential is output from the output terminal, both of the two transistors are turned on and then one of them is turned off. Thus, change in characteristics of the transistor can be suppressed and an output signal can be changed sharply without increasing W/L of the transistor.