A breath component measurement apparatus 1 includes a breath residence case 2. The breath residence case 2 includes a container 21 in the shape of a rectangular parallelepiped, an intake pipe 22 in the shape of a circular tube which is provided at the center of a front face of the container 21, a pump 23 which is formed over the whole right side surface of the container 21, a sensor storage unit 24 in the shape of a circular tube which is provided at the center of a bottom surface of the container 21, a gas sensor 25 which has the shape of a circular column and is stored in the sensor storage unit 24, a disk-shaped piezoelectric element 26 which is supported by a groove in a slot 27, the slot 27 that is formed on a left side surface of the container 21 and has the groove supporting the piezoelectric element 26, and an exhaust port 28 which is provided at a position hidden behind a back face of the piezoelectric element 26 of the left side surface of the container 21.
