A multilayer vessel being an ampule, vial, cartridge, prefilled syringe, infusion vessel, or multilayer syringe barrel for prefilled syringe; and comprising: a layer (X) that contains at least one type of polyolefin resin which accounts for 70% by mass or more of the layer (X); and a layer (Y) that contains a polyamide resin (A) which accounts for 70 to 100% by mass of the layer (Y), the polyamide resin (A) being composed of a structural unit derived from a diamine, and a structural unit derived from a dicarboxylic acid, 70 mol% or more of the structural unit derived from a diamine being derived from metaxylylenediamine, meanwhile 30 to 59 mol% of the structural unit derived from a dicarboxylic acid being derived from a straight chain aliphatic α,ω-dicarboxylic acid having 4 to 20 carbon atoms, and 70 to 41 mol% being derived from isophthalic acid; and when the multilayer vessel is a multilayer syringe barrel for prefilled syringe, the layer (X) contains 70% by mass or more of (i) a cycloolefin-based polymer having a glass transition temperature of lower than 100°C, preferably having a glass transition temperature measured according to JIS K7122 of 50 to 90°C, or (ii) at least one polymer selected from a polypropylene-based polymer and a cycloolefin-based polymer having a glass transition temperature measured according to JIS K7122 of 100°C or higher, preferably at least one polymer selected from said cycloolefin-based polymer. a layer (X) that contains at least one type of polyolefin resin which accounts for 70% by mass or more of the layer (X); and a layer (Y) that contains a polyamide resin (A) which accounts for 70 to 100% by mass of the layer (Y), the polyamide resin (A) being composed of a structural unit derived from a diamine, and a structural unit derived from a dicarboxylic acid, 70 mol% or more of the structural unit derived from a diamine being derived from metaxylylenediamine, meanwhile 30 to 59 mol% of the structural unit derived from a dicarboxylic acid being derived from a straight chain aliphatic α,ω-dicarboxylic acid having 4 to 20 carbon atoms, and 70 to 41 mol% being derived from isophthalic acid; and when the multilayer vessel is a multilayer syringe barrel for prefilled syringe, the layer (X) contains 70% by mass or more of (i) a cycloolefin-based polymer having a glass transition temperature of lower than 100°C, preferably having a glass transition temperature measured according to JIS K7122 of 50 to 90°C, or (ii) at least one polymer selected from a polypropylene-based polymer and a cycloolefin-based polymer having a glass transition temperature measured according to JIS K7122 of 100°C or higher, preferably at least one polymer selected from said cycloolefin-based polymer. (i) a cycloolefin-based polymer having a glass transition temperature of lower than 100°C, preferably having a glass transition temperature measured according to JIS K7122 of 50 to 90°C, or (ii) at least one polymer selected from a polypropylene-based polymer and a cycloolefin-based polymer having a glass transition temperature measured according to JIS K7122 of 100°C or higher, preferably at least one polymer selected from said cycloolefin-based polymer. <EOS>