NOVELTY - A photoelectric conversion element (10) consists of substrate (1), primary electrode (2), semiconductor (5), photoelectric converting layer (6) containing 3,5-dihydro-imidazol-4-one compound (I) as sensitizing dye (4), solid positive hole transport layer (7), and secondary electrode (8). The solid positive hole transport layer comprises polymer formed by polymerizing thiophene-containing compound (II), or multimer of thiophene-containing compound.    USE - Photoelectric conversion element is used for solar cell (claimed).    ADVANTAGE - The photoelectric conversion element has excellent photoelectric conversion efficiency and durability.    DETAILED DESCRIPTION - A photoelectric conversion element consists of substrate, primary electrode, semiconductor, photoelectric converting layer containing 3,5-dihydro-imidazol-4-one compound of formula (I) as sensitizing dye, solid positive hole transport layer, and secondary electrode. The solid positive hole transport layer comprises polymer formed by polymerizing thiophene-containing compound of formula (II), or multimer of thiophene-containing compound.    Ar1=optionally substituted aromatic ring-containing group;    R1,R2=H, cyano, amino, or linear or branched 1-24C alkyl, linear or branched 1-24C alkenyl, linear or branched 1-24C alkynyl, 6-24C aryl, linear or branched 1-24C acyl or heterocyclyl (all optionally having substituent);    n=1 or more;    X=single bond, sulfur, oxygen, selenium or -N(R5)-;    R3,R4=H, halo, hydroxy, thiol, cyano, amono, or linear or branched 1-24C alkyl, 6-24C aryl, linear or branched 1-24C alkenyl, linear or branched 1-24C alkynyl, 1-18C alkoxy or heterocyclyl (all optionally having substituent);    or R3+R4=ring;    R5=H, or linear or branched 1-24C alkyl, 6-24C aryl or heterocyclyl (all optionally having substituent);    Y1,Y2=-OR6;    R6=linear or branched 1-24C alkyl;and    or Y1+Y2=ring.    DESCRIPTION OF DRAWING(S) - The drawing shows schematic view of photoelectric conversion element.    Substrate (1)    Primary electrode (2)    Sensitizing dye (4)    Semiconductor (5)    Photoelectric converting layer (6)    Solid positive hole transport layer (7)    Secondary electrode (8)    Photoelectric conversion element (10)