To provide a three-way selector valve capable of saving an occupancy space by restraining a protruding amount of a ceramic valve cartridge, and capable of improving a freedom degree of layout such as an installation place or an installation direction.

The ceramic valve cartridge 3 is provided with a ceramic movable valve disk 48 turning interlockingly with opening and closing operation of a handle 4, and a ceramic fixed valve disk 50 slidably abutting on the movable valve disk 48 and unturnably. The ceramic valve cartridge 3 is housed in a housing chamber 25 of a valve housing 2, a bypass flow passage 26 bypassing the housing chamber 25 is formed between a wall surface of the housing chamber 25 and an outer peripheral surface of the valve housing 2. A main flow passage X is defined by the wall surface of the housing chamber 25 and a water inlet side end of the ceramic valve cartridge 3, and a branch flow passage Y is formed by communicating the bypass flow passage 26 with a valve outlet port 31b arranged in the valve housing 2.