A carrot is sliced in the longitudinal direction in such a way that the slice surface passes through the core portion, the sliced carrot fragment is blanched and the blanched carrot fragment is extracted to obtain a vegetable extract, so as to manufacture a vegetable extract. By slicing the carrot in the longitudinal direction so as to pass through the core portion, a larger area of the core portion towards which the presence of nitrate ions is biased can be exposed, the contact area between the core portion and the blanching water can be increased and more nitrate ions can be eluted and removed at blanching time.