[Problem] To provide a medicine packaging apparatus that allows the detection of medicine flowing out of a packaging bag to be detected when the medicine should be properly packaged. [Solution] The medicine packaging apparatus 10 comprises: a packaging paper supply unit 42 for supplying a packaging paper S for packaging a medicine M； a sealing device 50 for forming a packaging bag P by bonding the packaging paper S supplied from the packaging paper supply unit 42 in a folded state； a medicine introducing unit 80 for introducing the medicine M to the unsealed packaging bag P formed by the sealing device 50 through an open portion of the packaging bag P； a detection unit 90 for detecting the presence of the medicine M in a path in which the medicine M is introduced by the medicine introducing unit 80； and a determination unit capable of determining that a packaging error has occurred when the detection unit 90 detects the presence of the medicine M within a period from the timing when the sealing of the packaging bag P containing the medicine M is initiated to the timing when the medicine M is introduced into a following packaging bag P via the medicine introducing unit 80.
