A network protection device includes a packet capture unit which captures a network packet through an intelligent switch which performs connection in a communication network or across communication networks; a network analyzer which detects a threat in the network packet; a threat remover which removes the threat in the network packet; and a switch operator which changes from a first communication path, which connects a sender node to a receiver node without the threat remover, to a second communication path, which is different from the first communication path and connects the sender node to the receiver node through the threat remover when the threat is detected in the threat detector.