A photoelectrochemical cell (1) is a photoelectrochemical cell for decomposing water by irradiation with light so as to produce hydrogen. This photoelectrochemical cell (1) includes: a conductive substrate; a first electrode (optical semiconductor electrode (3)) including an optical semiconductor and disposed on a first main surface of the conductive substrate; a second electrode (counter electrode (4)) disposed in a region on the first main surface of the conductive substrate where the first electrode is not disposed; an electrolyte containing water and disposed in contact with a surface of the first electrode and a surface of the second electrode; a rib (5) formed to separate a space above the surface of the second electrode from a space above the surface of the first electrode and to extend along a flow direction of a gas produced on the surface of the second electrode, the rib being formed of a material that allows ions to pass therethrough and prevents a gas from passing therethrough; and a container (2) containing the conductive substrate, the first electrode, the second electrode, the electrolyte, and the rib.