The activities of glucose oxidase (GOx) and lactate oxidase (LOx) immobilized on a substrate were obtained as images of oxidation currents of H2O2 using a Bio-LSI system. In the presence of appropriate substrates, the image of the enzyme appeared as lines with a high oxidation current. The time required to obtain the current image was 10s, a significant decrease from the time required by the scanning method with a miniaturized probe.