A medical circuit board includes a substrate on which a wiring pattern is formed, a plurality of electronic components mounted in a mounting area on the substrate, a resinous sealing member covering the plurality of electronic components, with which the plurality of electronic components are sealed to the substrate, and a detection unit provided in an area other than the mounting area on the substrate and detecting an infiltration of a liquid from an interface between the substrate and the sealing member into the mounting area. At least a part of the detection unit is covered with the sealing member and sealed with the sealing member to the substrate.