A gelator that includes a lipid peptide of Formula (1) wherein R1 is a C9-23 aliphatic group, R2 is a hydrogen atom or a C1-4 alkyl group optionally having a C1-2 branched chain, R3 is a —(CH2)n—X group, n is a number from 1 to 4, and X is an amino group, a guanidino group, a —CONH2 group, or a 5-membered ring optionally having 1 to 3 nitrogen atoms, a 6-membered ring optionally having 1 to 3 nitrogen atoms, or a fused heterocycle including a 5-membered ring and a 6-membered ring that optionally has 1 to 3 nitrogen atoms; or a pharmaceutically usable salt of the lipid peptide.