MEASURING IMPLEMENT, MEASURING SYSTEM AND MEASURING METHOD

[Problem] To provide a measuring equippment which can be easily mounted to an internal combustion engine. [Solution] A measuring equippment (30) is equipped with: a measurement container (31) having formed therein a chamber (34) to be measured, into which a gas to be measured enters, and an inlet passage, through which the gas to be measured is introduced into the chamber (34) to be measured; and a connection structure (32) which, when a plug is not mounted to a plughole (25) that opens into a combustion chamber (24) in an internal combustion engine (20), connects the inlet passage to the plughole(25). The measurement container (31) may be provided with a plasma generation device (45), which generates plasma in the chamber (34) to be measured, or a mounting structure for mounting a heating device, which heats the gas to be measured in the chamber (34) to be measured.