An object of the present invention is to smoothly bend a nursing bed having a three-dimensional network structure made of a thermoplastic resin in multiple stages in response to complicated movements of a bed main body and specific movements of a user. The three-dimensional network structure 101 has a first three-dimensional dense structure 1 in which sparse structural units 1a1 to 1a9 and dense structural units 1b1 to 1b8 are repeatedly provided in the extrusion direction Y. In the first three-dimensional dense structure 1, The bulk density δ1 of the sparse structural units 1a1 to 1a9 is 0.01 to 0.08 g / cm3, the bulk density δ2 of the dense structural units 1b1 to 1b8 is 0.03 to 0.10 g / cm3, and the sparse structural units 1a1 to 1a1. The bulk density ratio δ2 / δ1 of the dense structural units 1b1 to 1b8 to 1a9 is 1.01 to 5, the length A1 of the sparse structural units 1a1 to 1a9 is 1 to 50 cm, and the length of the dense structural units 1b1 to 1b8 A2 is 3 to 60 cm, and the length ratio A2 / A1 of the dense structural units 1b1 to 1b8 to the sparse structural units 1a1 to 1a9 is 0.1 to 10.熱可塑性樹脂から構成される三次元網状構造体を有する介護ベッドを、ベッド本体の複雑な動きや、使用者の特定の動きに対応させて、円滑に多段階に曲げることを目的とする。三次元網状構造体１０１は、押出方向Ｙに疎の構成単位１ａ１～１ａ９と密の構成単位１ｂ１～１ｂ８とを繰り返し設ける第１立体疎密構造１を有し、この第１立体疎密構造１において、疎の構成単位１ａ１～１ａ９の嵩密度δ１は０．０１～０．０８ｇ／ｃｍ３、密の構成単位１ｂ１～１ｂ８の嵩密度δ２は０．０３～０．１０ｇ／ｃｍ３、疎の構成単位１ａ１～１ａ９に対する密の構成単位１ｂ１～１ｂ８の嵩密度の比率δ２／δ１が１．０１～５、疎の構成単位１ａ１～１ａ９の長さＡ１は１～５０ｃｍ、密の構成単位１ｂ１～１ｂ８の長さＡ２は３～６０ｃｍ、疎の構成単位１ａ１～１ａ９に対する密の構成単位１ｂ１～１ｂ８の長さの比率Ａ２／Ａ１が０．１～１０である。
