The present invention provides an injection needle device for an endoscope that can prevent an injection needle from unintentionally being exposed. An injection needle device for an endoscope comprises an outer tubular body (20), an inner tubular body (30) provided in the outer tubular body (20) and an injection needle (50) inserted into one end part of the inner tubular body (30), wherein the inner tubular body (30) includes an inner layer (31) and an outer layer (35) directly or indirectly contacted with an outer surface of the inner layer (31), and a water absorption coefficient of the outer layer (35) is lower than that of the inner layer (31).
