This application relates to a modular electrostatic precipitator. In one aspect, the modular electrostatic precipitator includes a housing providing a flow path through which air is moved and a charging module configured to emit electromagnetic waves to the air. The precipitator may also include a first attaching/detaching unit configured to attach and detach the charging module to and from the housing and a particle collecting module configured to collect particles in the air by applying an electrostatic force to the air. The precipitator may further include a second attaching and detaching unit configured to attach and detach the particle collecting module to and from the housing.