A coolant flow field is formed between first and second metal separator plates of a joint separator (fuel cell separator). First and second beads protrude from the first and second metal separator plates. The beads include inner beads for preventing leakage of a reactant gas. An air release passage and a coolant drain passage extend through the fuel cell separator in a separator thickness direction, and the air release passage and the coolant drain passage are connected to a coolant flow field through a first connection channel and a second connection channel formed by recesses on the back of protrusions of the first and second beads.