Dehumidifier

A dehumidifier which is to be connected to a respiratory gas measuring apparatus, the dehumidifier comprising:

• a membrane dryer having a first flow path through which a respiratory gas of a subject passes, a second flow path through which a gas that is smaller in water content than the respiratory gas passes, and a membrane that separates the first flow path and the second flow path from each other;
• a first normally-closed electromagnetic valve which is disposed in a first upstream flow path that communicates with the first flow path;
• a second normally-closed electromagnetic valve which is disposed in a first downstream flow path that communicates with the first flow path;
• a third normally-closed electromagnetic valve which is disposed in a second upstream flow path that communicates with the second flow path;
• a fourth normally-closed electromagnetic valve which is disposed in a second downstream flow path that communicates with the second flow path;
• a cooling device which cools the membrane dryer;
• and
• a heat radiating member which dissipates heat generated by the cooling device,
• wherein a gas which flows through the second downstream flow path passes through the heat radiating member.