A MEMS resonator comprising: a resonator body comprising a first spring-mass section and a second spring-mass section, each spring-mass section comprising a compound spring structure having a base end and an open end and a mass (60a, 60b) attached to the open end of the compound spring structure, the first and second spring-mass sections being connected at the base ends which form a pair of nodal points of minimum movement of the resonator body during resonant vibration of the resonator body, wherein the compound spring structure is formed from two or more spring unit cells stacked and connected backside-to-backside to form the compound spring structure and each spring unit cell comprises a compact folded spring structure consisting of two parallel backside beams, two pairs of parallel outer side beams, two pairs of parallel inside beams, and two parallel inner side beams, wherein the two parallel backside beams form two outer backsides of the spring unit cell, each of the two pairs of outer side beams extend orthogonally at the respective ends of the two parallel backside beams towards the inside of the spring unit cell, and each of the two pairs of parallel inside beams extends orthogonally at the respective ends of the two pairs of parallel outside beams towards the inside of the spring unit cell, and each pair of parallel inside beams is connected orthogonally to one of the two parallel inner side beams, so that a folded inner section is formed by a pair of parallel inside beams and an inner side beam, thereby forming two opposing folded inner sections that are concave when viewed from the outer side and whose inner side beams lie symmetrically opposite and parallel to each other when viewed in a plan view; a pair of anchors connected to a substrate and attached to opposite sides of the resonator body at the nodal points; a drive electrode formed attached to the substrate and capacitively coupled to the mass of the first spring-mass section; and a sense electrode formed attached to the substrate and capacitively coupled to the mass of the second spring-mass section. a resonator body comprising a first spring-mass section and a second spring-mass section, each spring-mass section comprising a compound spring structure having a base end and an open end and a mass (60a, 60b) attached to the open end of the compound spring structure, the first and second spring-mass sections being connected at the base ends which form a pair of nodal points of minimum movement of the resonator body during resonant vibration of the resonator body, wherein the compound spring structure is formed from two or more spring unit cells stacked and connected backside-to-backside to form the compound spring structure and each spring unit cell comprises a compact folded spring structure consisting of two parallel backside beams, two pairs of parallel outer side beams, two pairs of parallel inside beams, and two parallel inner side beams, wherein the two parallel backside beams form two outer backsides of the spring unit cell, each of the two pairs of outer side beams extend orthogonally at the respective ends of the two parallel backside beams towards the inside of the spring unit cell, and each of the two pairs of parallel inside beams extends orthogonally at the respective ends of the two pairs of parallel outside beams towards the inside of the spring unit cell, and the two parallel backside beams form two outer backsides of the spring unit cell, each of the two pairs of outer side beams extend orthogonally at the respective ends of the two parallel backside beams towards the inside of the spring unit cell, and each of the two pairs of parallel inside beams extends orthogonally at the respective ends of the two pairs of parallel outside beams towards the inside of the spring unit cell, and each pair of parallel inside beams is connected orthogonally to one of the two parallel inner side beams, so that a folded inner section is formed by a pair of parallel inside beams and an inner side beam, thereby forming two opposing folded inner sections that are concave when viewed from the outer side and whose inner side beams lie symmetrically opposite and parallel to each other when viewed in a plan view; a pair of anchors connected to a substrate and attached to opposite sides of the resonator body at the nodal points; a drive electrode formed attached to the substrate and capacitively coupled to the mass of the first spring-mass section; and a sense electrode formed attached to the substrate and capacitively coupled to the mass of the second spring-mass section.