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