The present invention relates to a fluid mixer having a fluid inlet (5), a first passage (1) which connects to the fluid inlet, a helical flow passage (2) which connects to the first flow passage, branched flow passages (4) which are branched from the helical flow passage, a second flow passage (3) to which the branched flow passages individually connect, a connection flow passage (7) which connects the first flow passage and the second flow passage, and a fluid outlet (6) which connects to the second flow passage. The branched flow passages are individually branched from different positions in the direction of flow through the helical flow passages. The branched flow passages which are branched from the helical flow passage individually connect to the second flow passage at different positions in the direction of flow through the second flow passage.
