An object of the present invention is to provide lipid particles which have low cytotoxicity, can stably hold nucleic acid molecules outside cells, and can promptly release nucleic acids in cytoplasm after escaping from endosome, and a nucleic acid delivery carrier. According to the present invention, there are provided lipid particles containing a compound represented by the following General Formula (1), sterol, at least one lipid selected from the group consisting of a neutral lipid and a lipid having a polyethylene glycol chain, and nucleic acids, and a nucleic acid delivery carrier. In the formula, R1 and R2 are the same as or different from each other, and are alkyl groups having 10 to 22 carbon atoms.