Proposed are an electromagnetic interference (EMI) filter for preventing noise emitted from a power line cable, and an isolated type active EMI filter having no additional elements on a power line. The EMI filter includes a common-mode (CM) choke disposed on a power source side, a Y-cap disposed on an EMI source side, and a sensing winding configured to sense a current. The EMI filter also includes an amplifier configured to amplify the noise current, and a transformer configured to inject a signal of the secondary coil into the Y-cap as a compensation signal.