A piezoelectric/electrostrictive porcelain composition capable of being manufactured at a comparatively low firing temperature is provided, as well as a piezoelectric/electrostrictive ceramic or a piezoelectric/electrostrictive portion which is dense and superior in crystallinity and which has superior piezoelectric/electrostrictive characteristics and durability even under high temperature and high humidity conditions. The piezoelectric/electrostrictive porcelain composition includes a piezoelectric/electrostrictive component containing lead titanate zirconate, and 0.5 to 5% by mass of glass component containing 8% by mass or less of silicic acid.