The present invention relates to a method for manufacturing food using marine algae, which comprises the following steps: (a) pulverizing marine algae to obtain fragments of the marine algae (b) depositing the fragments of the marine algae, together with basic salt, into a vacuum agitator to proceed with heating agitation at a temperature of 40-80 DEG C to obtain a paste of marine algae and (c) gelatinizing the paste of marine algae with a solution of metal ions having valence of at least two in order to obtain a marine algae gel. The present invention preserves the original color, smell, and taste of the marine algae and does not cause any loss or variance of the composition of the marine algae that is effective to human body.
