The purpose of the present invention is to provide a lithium ion-conductive ceramic material having high ion conductivity, and to provide a lithium battery having high capacity and high output as a result of using such a lithium ion-conductive ceramic material. Provided is a lithium ion-conductive ceramic material having an Li-containing first crystal phase where the crystal structure is a garnet-type structure or similar to a garnet-type structure and a second crystal phase containing Li, Mg, Zr, and O. In a specific region of the cross section, the ratio (L2/L1), where L1 is the total lengthof the line segments alternately joining successive crests and troughs in the surface of the lithium ion-conductive ceramic material and L2 is the total length of the line segments joining successivetroughs only, is at least 0.95 but smaller than 1. Also provided is a lithium battery including the lithium ion-conductive ceramic material as a solid electrolyte layer or protective layer.