A measurement apparatus includes a plurality of modules and a main unit for collecting measurement data output from the modules. The housing of the main unit can be carried by a user of the measurement apparatus, and the plurality of modules are removably accommodated in the housing. A controller area network interface circuit of the main unit collects the measurement data output from the modules accommodated in the housing. A main CPU of the main unit outputs the collected measurement data to, for example, a personal computer connected to the main unit. An internal memory and a USB memory connected to a USB memory module store the collected measurement data.