The ~/Library folder is hidden in Finder by default in Mac OS X. Library folder is used by apps to store app related data and is not meant for end users to access. This is Apple’s way of locking down folder to protect users from modifying or deleting any files or folders under ~/Library.
Sometimes, you might be required access to the Library folder in order to troubleshoot issues. Care must be given when you’re accessing the Library folder, or else your Mac or apps might not work properly.
Access using Option key
To access the ~/Library folder, hold down the Option key while looking at the Go menu in Finder.
Access using “Go to Folder”
An alternative is to select the option “Go to Folder” under the Go menu or using the shortcut keys Command+Shift+G. Enter “~/Library” under the “Go to the folder” prompt.
Permanently make the ~/Library folder visible in Finder
Open Terminal app under Applications>Utilities. On the command line, enter the following to permanently display Library folder under Finder:
chflags nohidden ~/Library/
To hide the Library folder, enter the command:
chflags hidden ~/Library/
Access via Terminal app
Using Terminal app, you can easily access ~/Library folder using the “cd” command line. You can also open Library folder under Finder window by using the command line “open ~/Library”.