A substrate processing method for removing reaction products generated in etching an etching target layer included in a target object by using a substrate processing apparatus including: a processing chamber defining a space; a partition plate which is disposed in the processing chamber and partitions the space into a plasma generating space and a substrate processing space, the partition plate being configured to suppress transmission of ions and vacuum ultraviolet rays; a plasma source (150A, 150B) configured to generate a plasma in the plasma generating space; a mounting table disposed in the substrate processing space for mounting the target object thereon; a first processing gas supply unit configured to supply a first processing gas into the plasma generating space, the first processing gas to be dissociated by the plasma to generate radicals; and a second processing gas supply unit configured to supply a second processing gas into the substrate processing space, the second processing gas reacting with the reaction products without being exposed to the plasma, characterized in that the substrate processing method comprises: generating the radicals by supplying the first processing gas from the first processing gas supply unit into the plasma generating space in which a plasma is generated; moving the generated radicals into the substrate processing space to cause a reaction with the reaction products; and supplying the second processing gas from the second processing gas supply unit into the substrate processing space to cause a reaction with the reaction products, wherein the etching target layer includes a metal-containing layer, and wherein the reaction products are removed by the interaction between the radicals and the second processing gas. a processing chamber defining a space; a partition plate which is disposed in the processing chamber and partitions the space into a plasma generating space and a substrate processing space, the partition plate being configured to suppress transmission of ions and vacuum ultraviolet rays; a plasma source (150A, 150B) configured to generate a plasma in the plasma generating space; a mounting table disposed in the substrate processing space for mounting the target object thereon; a first processing gas supply unit configured to supply a first processing gas into the plasma generating space, the first processing gas to be dissociated by the plasma to generate radicals; and a second processing gas supply unit configured to supply a second processing gas into the substrate processing space, the second processing gas reacting with the reaction products without being exposed to the plasma, characterized in that the substrate processing method comprises: generating the radicals by supplying the first processing gas from the first processing gas supply unit into the plasma generating space in which a plasma is generated; moving the generated radicals into the substrate processing space to cause a reaction with the reaction products; and supplying the second processing gas from the second processing gas supply unit into the substrate processing space to cause a reaction with the reaction products, generating the radicals by supplying the first processing gas from the first processing gas supply unit into the plasma generating space in which a plasma is generated; moving the generated radicals into the substrate processing space to cause a reaction with the reaction products; and supplying the second processing gas from the second processing gas supply unit into the substrate processing space to cause a reaction with the reaction products, wherein the etching target layer includes a metal-containing layer, and wherein the reaction products are removed by the interaction between the radicals and the second processing gas.