A low cost transdermal patch, which comprises water soluble microneedles and has good performance, and a method of manufacturing the same are provided. A transdermal patch (1 E) comprises a microneedle sheet (310), which comprises a plurality of water soluble microneedles (311), moisture permeable sheet (320), wherethrough water vapor passes, and a reinforcing film (30E). The reinforcing film (30E) is adhered, by an adhesive layer (35) having an adhesive strength less than that of an adhesive layer (322), onto an outer surface (320b) of the moisture permeable sheet (320), which is the side opposite the skin opposing surface (320a). The reinforcing film (30E) includes a water vapor barrier sheet (31), which blocks the passage of water vapor through at least a first area (Ar1), and a removable portion (32) around the water vapor barrier sheet (31). The removable portion (32) is configures such that it can be separated from and peeled off the water vapor barrier sheet (31).
