To provide a soap powder bag restraining the soap powder from becoming "lumps" in the bag and facilitating the soap powder to dissolve in washing water.

The soap powder bag 10 is provided with the cloth bag 2 able to house the soap powder and a fastener (catch) able to open/close the opening of the bag 2. A soap powder housing part S1 of the bag 2 is provided with an auxiliary housing part S2 partitioned by a meshy fabric and filled with lump-crushing granules 8. The granules 8 preferably include natural-rock grains 8A (ceramic grains) and further preferably artificial zeolite grains 8B (ion exchange material grains) for removing mineral components contained in the washing water such as calcium ions and magnesium ions.