For highly efficient and thermally stable inverted-type perovskite solar cells, we have developed non-fullerene electron transporting material (ETM) based on the aromatic N-substituted naphthalene-diimide(NDI) semiconductor. The NDI-PM ETM, (N,N'-Bis(phenylmethyl)naphthalene-1,4,5,8-tetracarboxylic diimide, exhibit comparable electron mobility and solubility compared to the fullerene based-PCBM ETM. Moreover, highly pure NDI-PM is cheaply synthesized by simple condensation reaction. The inverted-type perovskite solar cells with NDI-PM ETM were fabricated, i.e., glass/ITO/PEDOT:PSS/perovskite (MAPbI₃ or FAPbI_3-xBr_x)/NDI-PM/Al. The NDI-PM based-perovskite solar cells exhibit up to ~19.1 % power conversion efficiency (η) under forward scan condition and ~19.6 % η under reverse scan condition. Moreover, the perovskite solar cell with NDI-PM ETM retains almost an initial efficiency after 100 min heat-treatment at 90 °C.