中文摘要：

谱是泛函分析的重要概念之一.用初等方法得出了计数算子的谱,并且讨论了它的点谱和谱之间的关系.

英文摘要：

Spectrum is an important concept in functional analysis.This paper mainly discusses the spectrum of the number operator in an elementary way and shows the relationship between its point spectrum and spectrum.