Multilayer electronic component

A multilayer electronic component, comprising:

• a body including a dielectric layer and internal electrodes disposed alternately with the dielectric layer interposed therebetween;
• and
• external electrodes disposed on the body,
• wherein the dielectric layer includes:
• a main component including calcium (Ca), strontium (Sr), zirconium (Zr) and titanium (Ti) and a sub-component including manganese (Mn), yttrium (Y) and silicon (Si);
• and
• a plurality of dielectric grains and grain boundaries disposed between adjacent of the plurality of dielectric grains, wherein at least a portion of the plurality of dielectric grains has a core-shell structure that satisfies Ys/Yc>9,
• wherein Yc is a content of yttrium (Y) included in a core of the core-shell structure based on 100 moles of zirconium (Zr) included in the core and a shell, and
• Ys is a content of yttrium (Y) included in the shell based on 100 moles of zirconium (Zr) included in the core and the shell;
• wherein the dielectric layer further includes a secondary composition in at least a portion of the grain boundaries, and
• wherein an area fraction occupied by the secondary composition in the dielectric layer is 2.27% or more and 2.57% or less.