According to an aspect of the present disclosure, there is provided a polymerase chain reaction (PCR) patch which is provided as a gel type having a net-like structure forming micro-cavities, wherein at least a part of a plurality of reagents used in a PCR are contained in the micro-cavities, and when the patch contacts with an external region, the reagents contained in the micro-cavities move to at least a portion of the external region, and a PCR of a target DNA included in a sample located in the external region is performed.