The Excel ISNA function returns TRUE when a cell contains the #N/A error and FALSE for any other value, or any other error type.
- value – The value to check if #N/A.
Use the ISNA function to check if a value is #N/A. ISNA will return TRUE when value is #N/A
For example, =ISNA(A1) will return TRUE if A1 contains #N/A.
Normally, value is supplied as a cell address.
ISNA is part of a group of functions called the “IS functions”, which are often used to test the result of formulas for errors.