Therapeutic solution of an amount corresponding to a plurality of injections is injected with the distal end kept inserted in the pericardial cavity via an access port formed to penetrate under the xiphoid process. Provided is a therapeutic-solution injecting device (1) including an injection needle (3) for puncturing living tissue a tube (6) having the injection needle (3) at a distal end thereof a syringe connector (5) provided at a proximal end of the tube (6) and allowing connection and disconnection of a therapeutic-solution syringe (4) containing therapeutic solution and a three-way valve (8) provided in the tube (6) between the syringe connector (5) and the injection needle (3) and having an open end.