Analysis equipment is provided, which is capable of fulfilling a demand for miniaturization and ensuring high sensitivity, and which can be produced easily. The present invention relates to a method of continuously measuring a substrate concentration based on a response when a voltage is applied to a sensor. The present invention includes a response voltage application step of applying a response voltage E2 at which a response attributed to a substrate is obtained and a non-response voltage application step of applying a non-response voltage E1 at which the response attributed to the substrate is not obtained or is not substantially obtained. Preferably, the response voltage application step and the non-response voltage application step are repeated alternately.