Metal based networks are expected to be promising candidates to replace transparent conducting oxides such as indium tin oxide and doped zinc oxide in many kinds of optoelectronic devices such as displays and thin-film solar cells because they have lower sheet resistance, higher optical transmittance, and better mechanical flexibility than transparent conducting oxides. However, carrier transport in the empty spaces present in the metal networks has to be considered for the metal networks to be successfully integrated to real electronic devices. Therefore, it is still questionable for them to be appropriately implemented in real optoelectronic devices even though they have such advantages over transparent conducting oxides. Here, hierarchical networks composed of silver micromeshes and silver nanowires are presented. The hierarchical networks are successfully integrated to thin-film solar cells as transparent conducting electrodes by replacing transparent conducting oxides while they show low sheet resistance of ~2 ohm/sq, high optical transmittance of 88%. The silver micromeshes provides such low sheet resistance and high optical transmittance and the silver nanowires have role of ensuring carrier transport between empty spaces in the hierarchical network. In addition, they have excellent mechanical flexibility of no degradation of optoelectronic properties at a mechanical bending of radius of curvature of 5 mm.