An ESD protection device includes a substrate of a first conductivity type, a well region of a second conductivity type, a first doped region of the second conductivity type, a second doped region of the first conductivity type, a third doped region of the second conductivity type, a fourth doped region of the first conductivity type. The well region is configured in the substrate. The first doped region is configured in the well region. The second doped region is configured in the well region and surrounding the first doped region. The third doped region is configured in the well region and surrounding the first doped region and the second doped region. The fourth doped region is configured in the well region and under the first doped region and the second doped region. The fourth doped region is coupled with the first doped region and with the second doped region, respectively.