the fabrication process and characteristics of monolithically integrated urea and glucose fets are described. first, ion-selective fets (isfet) were fabricated on a sos substrate and a photosensitive dry film was coated on to it to form micropools over the isfet gates then mixtures of photosensitive pva and enzyme solutions were injected into these pools using microsyringes. after exposure to uv light, an insoluble membrane with enzyme entrapped in it was formed the proposed fabrication process is considered to be compatible with ic technology. urea and glucose concentrations in the range 1 $multiplied by$ 10** $minus$ **4 to 1 $multiplied by$ 10** $minus$ **2 g/ml could be detected by the urea and glucose fets, respectively. the integrated enzyme fets are useful for measuring several kinds of substrates simultaneously. the present fabrication process can be used for the preparation of multifunctional and one-chip biosensors with various other pairs of immobilized enzymes 12 refs