The present claimed invention is to provide a method for measuring a protein that enables to detect the protein with high accuracy and high sensitivity through an electrochemical method at a high speed with a simple operation using a simple device. With the method, a working electrode 5 and a counter electrode 4 are made to contact with a sample solution 1 containing the protein as being an object to be measured, and a voltage is impressed between the working electrode 5 and the counter electrode 4 so that a current value at the voltage can be measured and the protein can be electrochemically analyzed.