A medicine packaging apparatus 10 has a packaging paper supplying part 42； a sealing device 50 for forming a packaging bag； a medicine introducing part 80 for introducing the medicines M from an opening portion of the packaging bag P in an unsealed-state； a detecting part 90 for detecting presence of the medicines M in an introducing path for the medicines M by the medicine introducing part 80 and a determining part which can determine that a packaging failure occurs under a condition that the presence of the medicines M is detected by the detecting part 90 within a time period after a timing of starting to seal the packaging bag P in which the medicines M have been introduced and before a timing of introducing the medicines M to be packaged in a subsequent packaging bag P through the medicine introducing part 80.
