According to one embodiment, a simultaneous speech processing apparatus includes an acquisition unit, a speech recognition unit, a detection unit and an output unit. The acquisition unit acquires a speech signal. The speech recognition unit generates a decided character string and at least one candidate character string. The detection unit detects a first character string as a processing piece character string if the first character string included in the decided character string exists commonly in one or more combined character strings on dividing the one or more combined character strings by a boundary indicating a morphological position serving as a start position of a processing piece in natural language processing. The output unit outputs the processing piece character string.