The present invention aims to reliably prevent overcharge by carrying out charging in just proportion during charging periods.A charging apparatus 1 for charging a secondary cell 22 by supplying a charging current Ic thereto is provided with a discharge amount detector 62 for detecting an amount of power discharged from the secondary cell in a non-charging state, a charge amount detector 60 for detecting an amount of power charged into the secondary cell in a charging state, and a charger controller 10 for stopping charging when the amount of charged power (charge amount Wc) becomes equal to the amount of discharged power (discharge amount Wc) during a charging period.