Can the spouse work in Malaysia?

You just apply for jobs and if you get an offer of employment you give up your dependent pass and the employer will apply for an employment pass.

Thank you, Gravitas. All the procedure to get the EP is done in Vietnam or when i come to ML?

The application is done in Malaysia because it is a Malaysian company as the employer. If you have not yet arrived here, then part of the process will be done in Vietnam i.e. the single entry visa (VDR). Exactly the same way as will be happening for your husband. If you arrive and get the DP, then you don't have to leave the country, just exchange the DP for the EP.

Your husband's salary will have to be RM5000 or above for him to bring dependents and get you a DP

Thanks Gravitas. I feel more optimistic and hopeful.
The agency is helping us to get the EP for my husband and the DP for me and children.
We will come to ML when we have all EP and DP.
After that, as your infomation above, i can change DP to EP. Is the procedure difficult? Does it take time?
Maybe i will ask you later for more detail when i stand on ML land
Thank you so much, Gravitas

The EP and DP are endorsed into the passports AFTER arriving in Malaysia on the VDR.

You need a job offer and then the employer can apply for an EP.  The process shouldn't take longer than 3 weeks to complete.

You can already start applying for suitable vacancies online, but if a Malaysian can do the job, then it will not be offered to a foreigner, i.e. the employer will not be able to get an EP

Thank you, Gravitas.
Your information "... but if a Malaysian can do the job, then it will not be offered to a foreigner, i.e. the employer will not be able to get an EP" that means even if the company accepts me, the ML government also considers more for that position to provide me an EP?

Not really. The policy is for Malaysians to be recruited before foreigners are considered - it's called protectionism. The employer wanting to hire a foreigner has to prove it has not been possible to find the skills in the Malaysian workforce. Your ISO experience may therefore be helpful. But biotech is a very difficult  field in which to apply for jobs as a foreigner. The ASEAN mobility programme was recently introduced so it has become easier to be employed here. ASEAN nationals now have more opportunities