NOVELTY - A raw material and flux are mixed to form crystal precipitate, and raw material and flux are melted, cooled at temperature below eutectic point in temperature-fall rate of more than 50 degrees C/hour to obtain tantalate crystal particles having layered perovskite-type structure or layer structure having alkali metal-containing composition (1 or 2).    USE - Manufacture of tantalate crystal particles used for dye-sensitized solar cell (both claimed).    ADVANTAGE - The tantalate crystal particles provides solar cell having excellent photoelectric conversion characteristics.    DETAILED DESCRIPTION - A raw material and flux are mixed to form crystal precipitate, and raw material and flux are melted, cooled at temperature below eutectic point in temperature-fall rate of more than 50 degrees C/hour to obtain tantalate crystal particles having layered perovskite-type structure or layer structure having alkali metal-containing composition of formula: X( alpha )Y'( beta )Ta( gamma )O( delta ) (1), or alkaline-earth metal-containing composition of formula: Y'(zeta)Ta( eta )O( theta ) (2), where X is alkali metal, and Y'is alkaline-earth metal, and ( alpha ), ( beta ), ( gamma ) and ( delta ) satisfies relation: ( alpha )+2( beta )+5( gamma )=2( delta ), and (zeta), ( eta ) and ( theta ) satisfies relation: 2(zeta)+5( eta )=2( theta ), and ( gamma ) and ( eta ) are more than 1. An INDEPENDENT CLAIM is included for dye-sensitized solar cell, which has semiconductor electrode (2) in which pigment (3) containing metal oxide is adsorbed on surface, charge transferring layer (4) and counter electrode (5), on electroconductive base material (1). The tantalate crystal particles are contained as metal oxide.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional view of dye-sensitized solar cell. (Drawing includes non-English language text)    Electroconductive base material (1)    Semiconductor electrode (2)    Pigment (3)    Charge transferring layer (4)    Counter electrode (5)