The purpose of the present invention is to provide a system and method for administering a permeable liquid medicine, whereby: burdens both on a living body and on an operator can be reduced a loss in the liquid medicine can be minimized an optimum amount of the liquid medicine can be adjusted while stably keeping the liquid medicine even at a target administration site that is positioned against gravity the visual field at the administration site is not disturbed and the liquid medicine can be administered while confirming the administration effect.The administration system according to the present invention comprising a spray part (1) capable of spraying a permeable liquid medicine (20) from the side part of an endoscope tip (10) toward the surface of the inner wall (30) of a lumen in a living body, and a detection part (2) detecting the degree of the permeation of the liquid medicine, which is sprayed by the spray part, into an inner tissue of the inner wall of the lumen in the living body, wherein a first step for spraying the liquid medicine by the spray part toward the the surface of the inner wall of the lumen in the living body, and a second step for, after the first step, holding the spraying of the liquid medicine by the spray part on standby until the degree of the permeation of the liquid medicine into the inner tissue of the inner wall of the lumen in the living body, said degree being detected by the detection part, reaches a preset level, are repeated alternately so that a preset amount of the liquid medicine is intermittently administered in multiple portions to the inner wall of the lumen in the living body.La présente invention vise à fournir un système et un procédé pour administrer un médicament liquide perméable, grâce auxquels : des charges à la fois sur un corps vivant et sur un opérateur peuvent être réduites une perte de médicament liquide peut être réduite à un minimum une quantité optimale de médicament liquide peut être réglée tout en c
