Provided is a microbial fuel cell with which the dissolution of oxygen into a liquid from a liquid surface can be inhibited, and electrical energy recovery efficiency can be improved. A microbial fuel cell (1) according to the present invention is provided with: an organic-substance-containing liquid (4); anodes (2) disposed in the organic-substance-containing liquid (4); air cathodes (3) provided with air intake parts (11) for taking air into the air cathodes (3); and an oxygen blocking part (5) which stops the dissolution of oxygen into the organic-substance-containing liquid (4) from a liquid surface (4a) of the organic-substance-containing liquid (4).
