A method of checking a sealing state of a housing includes starting an operation of a pressure sensor configured to measure an internal pressure of the housing. The method includes checking whether or not the housing is pressed. The method further includes checking the sealing state of the housing through checking a measured value of the pressure sensor under a pressure of the housing. An apparatus for checking a sealing state of a housing includes the housing configured to keep an internal space thereof sealed off from an outside, a pressure sensor configured to measure a pressure of the internal space, and an interface unit configured to provide to the pressure sensor a control signal that controls an operation of the pressure sensor, and provide pressure information detected through the pressure sensor.