A flexible tube for an endoscope, comprising a flexible tube substrate, for an endoscope, that is flexible and tubular and a resin layer covering the flexible tube substrate for an endoscope, wherein the resin layer includes one or more layers, the layers including a layer A including a polyester elastomer (a) as a resin component, at least one of a phosphorus-containing compound or a thioether compound, and a hindered amine compound (c), the phosphorus-containing compound is a compound having a structure represented by general formula, the thioether compound is a compound having a structure represented by general formula, and the hindered amine compound (c) is a compound having a structural moiety represented by general formula: wherein in general formula, R 1 and R 2 represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, or a halogen atom; R 3 represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group; and at least two of R 1, R 2, or R 3 may be linked to each other via a divalent or higher-valent group or a single bond, in general formula, R 4 and R 5 represent a substituted or unsubstituted alkyl group and may be linked to each other via a divalent or higher-valent group or a single bond, and in general formula, R 6 to R 9 represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; R 10 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or -OR 11, wherein R 11 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and * represents a point of attachment; the recited alkyl and alkoxy groups are linear, branched or cyclic groups. wherein the resin layer includes one or more layers, the layers including a layer A including a polyester elastomer (a) as a resin component, at least one of a phosphorus-containing compound or a thioether compound, and a hindered amine compound (c), the phosphorus-containing compound is a compound having a structure represented by general formula, the thioether compound is a compound having a structure represented by general formula, and the hindered amine compound (c) is a compound having a structural moiety represented by general formula: wherein in general formula, R 1 and R 2 represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, or a halogen atom; R 3 represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group; and at least two of R 1, R 2, or R 3 may be linked to each other via a divalent or higher-valent group or a single bond, in general formula, R 4 and R 5 represent a substituted or unsubstituted alkyl group and may be linked to each other via a divalent or higher-valent group or a single bond, and in general formula, R 6 to R 9 represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; R 10 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or -OR 11, wherein R 11 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and * represents a point of attachment; the recited alkyl and alkoxy groups are linear, branched or cyclic groups. in general formula, R 1 and R 2 represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, or a halogen atom; R 3 represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group; and at least two of R 1, R 2, or R 3 may be linked to each other via a divalent or higher-valent group or a single bond, in general formula, R 4 and R 5 represent a substituted or unsubstituted alkyl group and may be linked to each other via a divalent or higher-valent group or a single bond, and in general formula, R 6 to R 9 represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; R 10 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or -OR 11, wherein R 11 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; and * represents a point of attachment; the recited alkyl and alkoxy groups are linear, branched or cyclic groups.