A semiconductor relay of the invention includes first and second signal terminals, a substrate, a first switch circuit and a control circuit. The substrate includes signal patterns for forming a signal line between the first and second signal terminals. The first switch circuit has a semiconductor switch used to make or break the connection between the first and second signal terminals. The control circuit has a control IC for controlling the first switch circuit. The control IC is mounted on a land of the substrate. The land has a size corresponding to the control IC. A part or all of the land is included in a part of the signal patterns.