An ESD protection device includes a ceramic multilayer substrate including a plurality of laminated insulating layers, an external electrode, at least one of an in-plane connecting conductor and an interlayer connecting conductor, and a mixture portion. The mixture portion is provided along a principal surface of one of the insulating layers and includes a dispersed material including at least one of metal and semiconductor; metal and ceramic; metal, semiconductor, and ceramic; semiconductor and ceramic; semiconductor; metal coated with an inorganic material; metal coated with an inorganic material and semiconductor; metal coated with an inorganic material and ceramic; and metal coated with an inorganic material, semiconductor, and ceramic. The mixture portion is connected to the external electrode and at least one of the in-plane connecting conductor and the interlayer connecting conductor.