To provide a cartridge for a self-closing faucet shortening the time required for disassembling work, further facilitating disassembling work, and further simplifying the maintenance work or the like, and to provide the self-closing faucet to be further miniatuarizable.

This cartridge 2 for a self-closing faucet includes: a first mechanism unit 20 structuring an operating portion 22 including a holder 26 and a spindle 24 connected to the holder 26; and a second mechanism unit 60 including a self-closing opening/closing valve 62 openable by axially pushing the holder 26, to automatically stop water with the self-closing opening/closing valve 62 closed after a preset discharge quantity of hot water is discharged. A first engagement portion 40 of the first mechanism unit 20 and a second engagement portion 72 of the second mechanism unit 60 are engaged with each other by using a quick fastener 100.