Concentrations of biological substances are useful as indicator of our health. In order to monitor biological substances, the minimally invasive device which does microdialysis in subepidermal tissue has been developed. Microdialysis needle has flow channel with dialysis membrane. It has been fabricated around a thin steel needle by our developed non-planer photofabrication process. Because this process is additionally applied, several shaped tubes and wires can be used as a base substance. Animal experiment was performed using mouse. Lactate concentration was measured as one of biological substance. Lactate was successfully collected with this needle.