We report on the search for new dielectric materials suitable for use in ceramic capacitors at high frequencies and temperatures by a large set of first-principles calculations. Crystal data of 3,382 candidate compounds were obtained from the Materials Project database. 2,393 compounds without an imaginary phonon mode were subjected to the computation of dielectric constants based on the density functional perturbation theory (DFPT). Among them 24 compounds exhibit a dielectric constant higher than 100, which is a benchmark value corresponding to a typical paraelectric material, rutile TiO2. The list of compounds of high dielectric constant includes not only known dielectric and/or piezoelectric materials, such as SrHfO3, KTaO3, and AgTaO3, but also compounds that are not generally used for such applications. Efforts to experimentally verify the high dielectric constant are under way.