A water trapping apparatus includes: a respiratory gas contacting portion that is disposed in a flow path through which a respiratory gas flows, and that is adapted to be in contact with the respiratory gas, the respiratory gas contacting portion that is comprised of a porous body and an ambient-air contacting portion that is formed integrally with the respiratory gas contacting portion, and that is adapted to be in contact with ambient air, the ambient-air contacting portion that is comprised of the porous body.
