Abstract: A polyester comprising acid monomer units of terephthalic acid, succinic acid, glutaric acid and isophthalic acid and/or an aliphatic dicarboxylic acid having 6 to 20 carbon atoms and glycol monomer units of a C.sub.2-10 alkylene glycol in specific proportions has been found to be extremely useful as hot-melt materials such as a hot-melt adhesive, a hot-melt coating material, a hot-melt sealing material and a hot-melt filling material. The present hot-melt polyester has excellent melting characteristics, that is, it can be rapidly molten from a solid state with a high sensitivity to heating to give a molten polyester having a stably low viscosity that does not almost undergo change according to variation of temperature and having an excellent fluidity. Further, the present hot-melt polyester has a good affinity for objects (e.g. adherend) to which the polyester is applied and exhibits excellent bonding or adhesive performance. Moreover, the present hot-melt polyester has improved suppleness and flexibility.