A semiconductor device is provided that is inexpensively manufactured with variation in high-frequency characteristics suppressed. Internal matching circuit boards are disposed on at least one signal transmission path of an input-side signal transmission path between an input terminal and a semiconductor element and an output-side signal transmission path between the semiconductor element and an output terminal and is provided for matching at least between output impedance of an external circuit connected to the input terminal and input impedance of the semiconductor device or between input impedance of an external circuit connected to the output terminal and output impedance of the semiconductor device, and components are electrically connected by at least one wire causing a change exceeding an allowable value in high-frequency characteristics of the semiconductor device due to a change in wire length and are disposed in contact with each other inside a package.